[show abstract][hide abstract] ABSTRACT: Complement C1s protease inhibitors have potential utility in the treatment of diseases associated with activation of the classical complement pathway such as humorally mediated graft rejection, ischemia-reperfusion injury (IRI), vascular leak syndrome, and acute respiratory distress syndrome (ARDS). The utility of biphenylsulfonyl-thiophene-carboxamidine small-molecule C1s inhibitors are limited by their poor in vivo pharmacokinetic properties. Pegylation of a potent analog has provided compounds with good potency and good in vivo pharmacokinetic properties.
[show abstract][hide abstract] ABSTRACT: Complement activation has been implicated in disease states such as hereditary angioedema, ischemia-reperfusion injury, acute respiratory distress syndrome, and acute transplant rejection. Even though the complement cascade provides several protein targets for potential therapeutic intervention only two complement inhibitors have been approved so far for clinical use including anti-C5 antibodies for the treatment of paroxysmal nocturnal hemoglobinuria and purified C1-esterase inhibitor replacement therapy for the control of hereditary angioedema flares. In the present study, optimization of potency and physicochemical properties of a series of thiophene amidine-based C1s inhibitors with potential utility as intravenous agents for the inhibition of the classical pathway of complement is described.
[show abstract][hide abstract] ABSTRACT: A number of fluorinated 1-aryl-tetrahydrocyclopentapyrazoles were synthesized and their insecticidal activity was evaluated. Some of the fluorinated compounds had significant insecticidal properties.
[show abstract][hide abstract] ABSTRACT: Through structure-based drug design and parallel synthesis, we have discovered a novel series of nonpeptidic phenyl-based thrombin inhibitors using oxyguanidines as guanidine bioisosteres. These compounds have been found to be highly potent, highly selective, and orally bioavailable.
[show abstract][hide abstract] ABSTRACT: Activation of the classical pathway of complement has been implicated in disease states such as hereditary angioedema, ischemia-reperfusion injury and acute transplant rejection. The trypsin-like serine protease C1s represents a pivotal upstream point of control in the classical pathway of complement activation and is therefore likely to be a useful target in the therapeutic intervention of these disease states. A series of thiopheneamidine-based inhibitors of C1s has been optimized to give a 70 nM inhibitor that inhibits the classical pathway of complement activation in vitro.
[show abstract][hide abstract] ABSTRACT: Pyrazole 2a is a novel, potent ligand for insect GABA receptors obtained from housefly head membrane preparations (K(i)=8 nM). It is 500-fold selective against the mammalian receptor (mouse brain preparations). Its specifically tritiated version (2b) was synthesized by reduction of disulfide 10 with NaBH(4) followed by alkylation with [3H(3)]-CH(3)I.
[show abstract][hide abstract] ABSTRACT: Although thrombin has been extensively researched with many examples of potent and selective inhibitors, the key characteristics of oral bioavailability and long half-life have been elusive. We report here a novel series non-peptidic phenyl-based, highly potent, highly selective and orally bioavailable thrombin inhibitors using oxyguanidines as guanidine-mimetics.
[show abstract][hide abstract] ABSTRACT: The discovery of novel 5,7-disubstituted[1,6]naphthyridines as potent inhibitors of Spleen Tyrosine Kinase (SYK) is discussed. The SAR reveals the necessity for a 7-aryl group with preference towards para substitution and that this in combination with 5-aminoalkylamino substituents further improved the potency of the compounds. The initial SAR as well as a survey of the other positions is discussed in detail.
[show abstract][hide abstract] ABSTRACT: A study of the S1 binding of lead 5-methylthiothiophene amidine 3, an inhibitor of urokinase-type plasminogen activator, was undertaken by the introduction of a variety of substituents at the thiophene 5-position. The 5-alkyl substituted and unsubstituted thiophenes were prepared using organolithium chemistry. Heteroatom substituents were introduced at the 5-position using a novel displacement reaction of 5-methylsulfonylthiophenes and the corresponding oxygen or sulfur anions. Small alkyl group substitution at the 5-position provided inhibitors equipotent with but possessing improved solubility.
[show abstract][hide abstract] ABSTRACT: Two methods are described for the regiospecific synthesis of 3,4-fused-cycloalkyl-1-arylpyrazoles; the key step is the reaction between aryl hydrazines and cyclic α-(dimethoxymethyl)ketones. The latter are obtained by BF3-promoted alkylation of ketones with trimethylorthoformate.
Tetrahedron Letters - TETRAHEDRON LETT. 01/2002; 43(48):8639-8642.
[show abstract][hide abstract] ABSTRACT: The serine protease urokinase plasminogen activator (uPA) is thought to play a central role in tumor metastasis and angiogenesis. Molecular modeling studies suggest that 5-thiomethylthiopheneamidine inhibits uPA by binding at the S1 pocket of the active site. Further structure based elaboration of this residue resulted in a novel class of potent and selective inhibitors of uPA.
[show abstract][hide abstract] ABSTRACT: The serine protease urokinase (uPa) has been implicated in the progression of both breast and prostate cancer. Utilizing structure based design, the synthesis of a series of substituted 4-[2-amino-1,3-thiazolyl]-thiophene-2-carboxamidines is described. Further optimization of this series by substitution of the terminal amine yielded urokinase inhibitors with excellent activities.
[show abstract][hide abstract] ABSTRACT: The structure activity relationships of a novel series of non-amide-based thrombin inhibitors are described. Exploration of the P2 and the aryl binding region for this series has identified optimal groups for achieving nanomolar potency. The binding modes of these optimal groups have been confirmed by X-ray structural analysis.
[show abstract][hide abstract] ABSTRACT: We expand the structural requirements and structure-activity relationship of a novel class of non-peptidic aryl-based thrombin inhibitors through exploration of the S1 specificity pocket of thrombin using flexible and constrained amidines. The most active compound of this class is 11 with Ki = 69 nM, which is ca. 15-fold less potent than constrained guanidine 5.
[show abstract][hide abstract] ABSTRACT: We describe a new class of potent, non-amide-based small molecule thrombin inhibitors in which an amidinohydrazone is used as a guanidine bioisostere on a non-peptide scaffold. Compound 4 exhibits nM inhibition of thrombin, is selective for thrombin, and shows 60 and 23% bioavailability in rabbits and dogs, respectively. Crystallographic analysis of 4 bound to thrombin confirmed the amindinohydrazone binding mode.
[show abstract][hide abstract] ABSTRACT: We describe the in vitro evaluation and crystallographic analysis of a new class of potent and selective, non-amino acid-based, small-molecule thrombin inhibitors, exemplified by 14. This class of achiral inhibitors lacks an amide-based backbone, exhibits nM inhibition of thrombin, and is selective for thrombin. Compound 14 does not interact with the active-site catalytic apparatus and is anchored to the enzyme via a single network of hydrogen bonds to Asp189 of the S1 pocket.